import java.util.ArrayList;
import java.util.List;

public class ThreadSafety {
    private static int count=0;
    private static Object locker=new Object();
    private static Object locker2=new Object();

    private static String s="hello";
    private static List<Integer> list=new ArrayList<>();
    private static int a=10;
    public static void main(String[] args) throws InterruptedException {
        Thread t1=new Thread(()-> {
          for(int i=0;i<50000;i++){
              synchronized (Demo1.class) {
                  count++;
              }
          }
        });
        Thread t2=new Thread(()-> {
            for(int i=0;i<50000;i++){
                synchronized (Demo1.class) {
                    count++;
                }
            }
        });
        t1.start();
        t2.start();
        t1.join();
        t2.join();
        System.out.println("count="+count);
    }
}
